A lot of the raw chestnuts that you buy in the market are not very fresh, and it is not uncommon to find, on opening, that they are moldy or have hardened into rocks.

The easiest and cheapest way to enjoy real roasted chestnuts is to buy them frozen from Trader Joe's--about $2.29 or so for a pound, you can warm them up in the oven for about ten minutes and they're all good.

Though not mentioned above, chestnuts, which were a significant part of the diet in the nineteenth century, were all but obliterated by a blight--nowadays, what few chestnuts you find are imported from Italy. They make the trip better if roasted and frozen first.